HUACA (Hang up and call again)
Unless PAL have had a change of heart, and I accept that airlines not meddling with 3rd party bookings is very much the norm, there is plenty of evidence upthread that PAL have handled the involuntary change for others who booked this deal.
Call again and try your luck. Different time of the day. If they still try to fob you off tell them that Bravofly/Lastminute have referred you to PAL as it is your (airline) change. It won't hurt.
When I called I was fairly certain that my conversation was handled back in the Philippines. Fingers crossed for you.